Metal working machine



June 7, 1949. A. J. BARRIE EI'AL METAL WORKING MACHINE s Sheets-Sheet 1 Filed March 28, 1945 INVENTOR. flrffiur J30 fr'le By Efg'yrr/ormJ 175 er 22,1 3; 6, ATTORN June 7, 1949.

A. J. BARRIE ETTAL METAL WORKING MACHINE s smu -sheet 2 Filed March 28 1945 June7, 1949. A. J. BARRIE ETAL METAL WORKING MACHINE Filed March 28.. 1945 Sheets-Shae 3 QNx Patented June 7, 1949 METALWORKING MACHINE Arthur J. Barrie and Raymond J. Dwyer, Toledo, Ohio, assignors to Acorn Designing 00., Toledo, Ohio, a corporation of Ohio Application March 28, 1945, Serial No. 585,224

Claims[ This invention relates to metal working machines and more especially to machines for impressing configurations in sheet metal and involves improvements upon the machine disclosed in and forming the subject matter of our copending application of Serial No. 554,259, filed September 15, 1944, nowIJ'. S. Patent No. 2,421,- 450.

The invention embraces the provision of mechanism for impressing grooves or annular recesses into the walls of cylindrical tubing or pipe fabricated of sheet metal.

The invention comprehends a machine especially adapted for rolling or impressing grooves in the exterior walls of muflier shells and is inclusive of means for supporting the shells during working operations so as to accommodate tubular members pre-assembled within and extending longitudinally of the shells.

An object of the invention resides in the provision of improved means for stripping a muffler shell from the supporting means after the completion of the grooving operation.

Another object is the provision of retractable work supporting meansfor a grooving machine particularly usable for performing operations upon muflier shells whereby ample clearance space is provided for inserting the work pieces or shells in the machine andremoving same therefrom.

Still another object is the provision of a work positioning abutment means resiliently or flexibly supported so as. to compensate for inaccuracies in the length of work shells and to accommodate shells in which the ends are rough or are not accurately cut to lie in planes perpendicular to the longitudinal axes of the shells.

Other objects and advantages are within the scope of this invention'such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elementsp'er se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

Figure 1 is a front elevational view of a grooving machine embodying the invention;

Figure 2 is an elevational View of a portion of the mechanism'illustrating our invention, certain parts being shown in section;

Figure 3 isan end elevational view of the machine shown in Figure 1;

Figure 4 is an end view of the structure illustrated in Figure 2, and

Figure 5 is a sectional view illustrating the work support in retracted position, and

Figure 6 is an end view showing circuit controlling means for actuating mechanisms forming part of the machine.

Figure 7 is an enlarged fragmentary sectional view of a portion of the construction illustrated in Figure 2.

While we have illustrated an embodiment of our invention as incorporated in a machine for rolling or impressing circumferential depressions or grooves in a thin walled cylindrical member as, for example, a muffler shell, it is to be understood that the arrangement of our invention may be used in connection with other mechanisms wherever it may be found to have utility. As illustrated, the machine is of the character forming the subject matter of our co-pending application above referred to, and is inclusive of means for preliminarily supporting the shell or other work, means for supporting the shell during work performing operations, groove impressing means, work discharging means and other cooperating mechanisms. The grooving machine will be described herein in such detail only as to show the incorporation operation and utility of our present invention therewith.

Referring to the drawings in detail the machine is inclusive of a frame or bed in having adjacent each end an upwardly extending boss H, and a horizontal longitudinally extending machined surface [2 disposed at a lower level in front ofbos ses ll. Mounted upon the surface I2 and arranged adjacent each end portion of the machine frame is a work-supporting means or work supporting 'mechanisms l5 and 16. As these units are of,"sfibstantially identical construction, a detaile escription of one of said units will suflic, ,,'Ih e'bed portion of the frame Iii adjacent the machined surface I2 is formed with a longitudinally extending T-shaped slot IT in which are disposed headed bolts l8 which are adapted'to receive nuts IQ for clamping the work supporting units l5 and IE to the machine frame. The lower surface of the unit resting upon the surface I2 is formed with a longitudinal keyway to accommodate a key 2|, said key extending into the throat portion of the T-shaped slotll, thus providing a means for maintaining the units in proper alignment on the frame [0.

Each of the units is arranged for longitudinal adjustment so as to accommodate work pieces of difierentlengths. To this end, pairs ofbrackets 23 and 24 are secured to each end portion of the machineframe and are bored to receive a shaft 25 having a squared end portion 26, the latter adapted to accommodate a suitable operating crank 28. Pinned or otherwise secured to each of the shafts 25 and arranged at either side of the brackets 23 are collars 21, so that during rotation of the shaft 25, the same will remain in a relatively fixed position. Secured to the side of the base or platen 29 of each unit is a laterally extending member 30 having a boss portion 3| bored and internally threaded to receive the threaded exterior portion 32 of shaft 25. Thus by releasing the nuts I9, the shafts 25 may be rotated by means of a crank to selectively adjust the units with respect to the machine frame for different lengths of work pieces.

Mounted upon the platen 29 is a member 34 which is keyed to the platen 29 by means of transversely extending keys '40 providing for lateral adjustment of the work supporting unit. The member 34 is formed with upwardly extending spaced lugs or projections 4| and 42, and disposed between the rojections is a housing or bracket 43 which supports and encloses the mechanism of each work supporting unit. The housing 43' and the projections 4| and 42 are provided with aligned bores or openings to receive stub shafts or pintles 44 which are held in place by means of set screws '45. ,The housing 43 is formed with a rearwardl'y extending portion 4'! which is provided with circular recesses '48 to receive coil springs '49. The portion 41 of the housing'is provided with threaded openings adapted to receive threaded studs which extend upwardly, and centrally through the coil springs 49 and are adaptedto receive a washer 5| and nuts 52 as shown inFigure 4. The tension of the springs 49 may be varied by adjusting the nuts 52. It should be. noted that the work supporting unit is capable 'of pivotal movement about the axes of stub shafts 44, resisted only by the springs '49. By this arrangement, damage to the machine in the eventjthat the grooving means does .not cooperate properly with the work is prevented as excessive pressure will compress the springs '49 and permit pivotal movement of the housing away from the grooving die.

'Each of the housings '43 of the units is formed with a hollow interior in which is disposed plain bearings 'or bushings 55 in which is slidably mounted a cylindrical sleeve. 56. The sleeve 56 is prevented from rotating by means of a key 5! mounted in a recess formed in the interior wall of one of the bearings 55v and projects into a keyway or slot '58 as s'h'o'wnin Figure 2. The interior end portions of thefsleeve 56 are recessed to accommodate the outer races of ball bearings 59 and 60. Mounted centrally of the bearings 59 and 60 is a shaft 63, the inner races of the ball bearings being suitably spaced by means of a sleeve 64. The one 'end of theshaft 63 is formed with a head 65 which forms an abutment for positioning the ball bearing 60, the other end of the shaft being provided with a threaded tenon 66 which receivessecuringnuts61 adapted to retain the bearings 59 and '60 in fixed relation upon shaft 63.

Secured upon the rear end 'of each of the members 43 by means of bolts 68is'a-s1eeve 69. Mounted upon the pro jectingend of sleeve 69 is a plate I0 to which is secureda fitting TI which supports a cylinder "I2 in which isjslidably mounted a ,piston I3, the piston and cylinder-forming an hypressure conveyed to the cylinder 4 draulic actuator for effecting longitudinal movement of the work supporting mandrel to be hereinafter described. The hydraulic connections are made by means of flexible tubes I4 and I5 connected respectively to the ends of the cylinder 12. The piston I3 is connected to piston rod 11, the latter having a threaded end extending into a plate 18, the rod 11 being locked in adjusted position by means of a nut I9. The plate I8 is-secured to the end of the longitudinally slidable sleeve 56 by means of screws 80. The piston rod 'I-I passes through a stufiing gland 8| contained within the fitting or member I I.

The end of shaft 63 is formed to carry the ,mufller shell or Work supporting and positioning means forming part of our invention. Mounted upon shaft "63 is a work supporting member or mandrel 84 which is secured to the shaft by means of a screw 85. The member 84 is connected. to rotate with shaft 63 by means of a pin 86, the member 84 being centered upon shaft 63 by means of an annular projection 87 engaging over a cylindrical tenon 88 formed on the end of shaft 63. The member 84 is recessed as at 90: to accommodate a projecting tube 9| which forms a part of the interior structure of 'a muflier 92. The exterior periphery of the mandrel "84 is formed with an annular groove or recess :94 to accommodate the formation of a depression or groove '95 in the mu'fller shell 92. The means for positioning the shell inwork performing position and for compensating for irregularities of the end edges of the muflier shell will 'be hereinafter described.

The. means for impressingthe clrcumferential' grooves in the shell is mounted upon a pair of supports or brackets I00, which are secured upon the surface II of the machine frame by means of bolts IOI. Journaled in suitable bearings carried in boss portions I0'2integrally formed with brackets I00 is alongitudinally extending shaft or arbor I03. Theright hand end of shaft I03 as viewedinFigure '1 supports an arm I05 which is secured to the shaft by means of a key I06 and a set screw I01. The arm I05 is bored at its extremity to receive a pin or pintle I08, a yoke I09 straddling the .arm I'05bein'g connected to the arm by means of vpin I08. ,Th'e yoke |09is adjustably connected to a rod I10 which projects into a cylinder H2 and is connected to a piston I13 slidable within the cylinder. The lower end of the cylinder is formed with a projection II'5 which is pivotally connected by means of a pin '6 to a bracket II], the latter secured to the lower rear wall of the machine frame by means of screWs IIS. v

Mounted upon shaft I03 a pair of similarly shaped spaced sectors or members 120. The shaft I03 is formed with a fiattenedsurface I21, and each sector I20 is provided with a rectangularly shaped key I22 which cooperates with screws Il23 for clamping the sectors I20 in adjusted position on shaft P01. The arcuate surface |24 'of each sector :is adapted to receive and support a segmental curvediblock or die I25- formedwith-a ridge or bead I 26 ,which is adapted to be brought into rolling engagement with the periphery-of the muffler shell 92 in order to impress a portion of "the shell .into the groove 94 in the work support 84 and hence to form the inwardly extending ridge or bead 95 in the shell. The sectors I20 and the grooving dies carried thereby are actuated by means of fluid under N2 and acting upon the piston II3,

The work supporting mandrel 84 is formed with a cylindrical surface I29 which is surrounded by an annular member I30 which is formed with a plurality of regularly spaced radially extending projections or lugs I3I. Disposed rearwardly thereof is a member I32 of annular configuration also having a plurality of radially extending projections I33 which are arranged for coincidence with projections I3I on member I30. The members I30 and I32 are secured together by means of screws I34. As illustrated in Figure '7, the members I30 and I32 are normally separated by a space I35, the head portions of screws I34 serving to limit the separation of said members. The registering projections I3I and I33 are formed. with cylindrical recesses I36 and I3], each pair of recesses being adapted to receive and enclose a coil spring I38. As indicated in Figure 4 there are nine pairs of projections, each set recessed to receive a spring. We have found that it is desirable to employ three sets of springs, each set of diiierent expansive force. The purpose of the employment of sets of springs of this character is to provide a means whereby the muffier shell, in engaging and abutting the member I30, will equalize and centrally position the'mu'ffier shell through the use of sets of springs I38. This is essential in order that the grooves to be formed in the muflier shell be arranged a substantially equal distance from each end of the shell, the springs I38 functioning to enhance the equalization so that each of the grooves to be formed in the shell will be equidistant from each end of the shell.

The projecting portion 81 of work support 84 is exteriorly threaded as at I4I to accommodate a threaded collar I39 which carries an annular member I40, the latter forming an abutment or limiting means for positioning member I32 By rotating members I30 and I40 through the use of a spinner wrench, an axial adjustment may be obtained of members I30 and I32 so as to provide a simple, yet effective means for controlling the distance from each end of the muilier to the groove 95 therein.

Surrounding members I30 and I32 is a cylindrically shaped sleeve or work stripping ring I42 having an exterior annular ridge I43 which is contained within recesses formed in the interior surfaces of retaining members I44 and I45 which surround sleeve I42. Retaining member I45 is secured to the housing 43 by means of screws I46, and retaining member I44 is secured to member I45 by means of screws I41. As will be seen from Figure 4, the member I44 is formed with slots M0 to accommodate the screws I41 so as to provide a means for quickly and easily disconnecting member I44 from member I45. This is accomplished by slightly releasing screws I41 and rotating member I44 in a counterclockwise direction as viewed in Figure 4 until the enlarged ends of slots I48 register with screws I4'I after which member I44 may be bodily removed from the machine.

The member I42 is formed with integral inwardly extending spaced projections I50 which inter-engage or dovetail with the radial projections I3I and I33 formed respectively on members I30 and I32 as shown in Figure 4. By this means the projections I3I and I33 are in driving engagement with the annulus I42, but members I30 and I32 may move axially into nesting relation with the member I 42 so that the front surface I49 thereof functions as an abutment to strip the grooved mulller shell from the work supporting mandrel after completion of the grooving operation.

The inner surface I53 of member I3I is arcuately shaped or of convex configuration as shown in Figure 7, which convex surface is in juxtaposition to the surface I29. By the provision of this configuration formed on the abutment ring or member I3I, the end of the mufiler shell may be slightly irregular and under such condition the abutment I3I may tilt slightly with respect to a plane at right angles to the axis of the work supporting mandrel so as to compensate for any such irregularity in the end edge of a muffler shell. The arcuate surface I53 eliminates the tendency of binding occurring between surfaces I29 and I53. "The end of the shaft I03 opposite the arm I05 is provided with a cam ring I55 equipped with switch operating blocks or cams I56 and I5'I which cooperate with switch arms I58 and I59 connected to switches I60 and IEI which are socured to the adjacent bracket I00. The switches I60 and IGI are intercalated in electric circuits (not shown) which control the operation of hydraulic valves (not shown) for controlling and directing fluid flow under pressure to and from the work supporting unit cylinders I2 and the groover actuating cylinder II2. As the electrical and hydraulic circuits per se form no part of the present invention and as they are disclosed in our co-pending application hereinbefore referred to, it is believed unnecessary to make further description of them herein.

Means are provided for preliminarily supporting the work piece or shell prior to the movement of the work supporting arbors 84 into work supporting positions. This means is inclusive of a pair of arms or levers I80 each pivoted to one of the work supporting units by means of a bolt or pivot shaft I8I. The short arm of each of the levers is pivotally connected as at I52 with a link I53, the lower end of each of the links being connected to a movable armature or core I04 which is activated by a solenoid I65, the circuit of which is intercalated with one of the switches arranged at the end of the shaft I03.

The operation and arrangement of the machine is substantially as follows:

As shown inFigure 1, a fluid reservoir I is housed within the machine frame I0, and arranged adjacent the reservoir is an hydraulic pump which is energized by a motor III which is brought into operation by closing a suitable switch (not shown) to drive the pump and set up hydraulic pressure for hydraulically actuating the several mechanisms hereinbefore described. Initially, the solenoids I65 are energized so as to maintain the levers or arms 80 in their uppermost positions as shown in Figure 4 and upon which a mufller shell or work piece is positioned by the machine operator. It is to be understood that when a mufller shell is mounted upon the levers I80, the work supportin means or mandrels 84 are in retracted position as shown in Figure 5, so as to provide at the ends of the muffler, ample space for the machine operator to manually fix or position the projecting tube portion 9| forming a part of a mufiier assembly so that the tube is in a position to project same into the recess 30 formed in the work supporting mandrel 84. The tube 9I forms an element of a pre-assembly that must be inserted into the shell before the grooving operation is made. After the muiiier shell 92 and the sub-assembly contained therein are in proper position, the

7 operator manipulates aswitch no't'shown) which actuates valve means to directilowoffluid under pressure from the "reservoir tothe'puter 'en'ds'of cylinders 12 throughth'e tubes "I4. 'The'fiuid acting'upon the pistons '73 drives each rod 11, shafts 63, and sleeves 56 "to move the worksupporting mandrels 84 in'to the ends of'the imifllerlsh'ell 92 to the position shown in Figure 1. The'memb'ers I31 and I33 are carried tforward with work'support 84 until the abutm'ent member ":I'3I engages the end edge of the muiller she'll. In the event that member "131 on one work supporting'unit engages the muifier shell in advanceoi the other abutment member, the springs I38 will equalize the position of the muffler shellso that the dis.- tance from the mufiier end edge to the point Zo'f application of thegroo'ving die 'willbe substantially 'equi-distant from each end of the shell. Should the end edge of the muffler shell or work piece be rough or irregular, the abutments'liil may tilt by reason of the arcuate'surface 153 to accommodate and compensate for such irregularities. When 'each'work supporting "mandre134 reaches its work supportingposit'ion as shown in Figure 3, the iiuid pressure in cylinders I2 attains a predetermined value and -is caused to actuate a merco'id'switch (not shown) which completes a circuit to the solenoid ofa' valve meansifor establishing a fluid flow under pressure to the upper end of the cylinder H2. The circuit to thesolenoids IE5 is interrupted so thatthe arms I89 swing downwardly a'boutlthe axes of shafts IIB I under the influence of gravity. Fluid pressure movesthe piston II3 downwardlyfin cylinder ILI2 and through the rod 'IIlland yOkeIIBB, causes rotation of shaft IE3 and the grooving elements I24. The movement of the elements 124 brings the .faces of die blocks I25.and the beads 126 into rolling engagement with the mufiier shell :92. As the beads I26 are in planes aligned with the grooves 94 formed in the work supporting mandrels 84, a pair of circumferential grooves 95 are impressed in the muffler shell 92. When the members I24 have completed grooving operation, the switch I6I is actuated :by-the block I56 to energize means (not shown) fordi'verting flow' of fluid to the lower end of cylinder I I2 to drive pistons I I3 upwardl and return the groovers I24 to their initial position. The switch meansadjacent the end of shaft 'I 03 cooperates with a cam carried by the shaft andactuate'valve' means to direct fluid flow through the tubes to the inner ends of the cylinders -12. The pistons I3 are thus reciprocated in the opposite direction and through the medium of shaft 65.,Isleeve 56 and associated elements, the work supporting mandrel 84 is retracted to the position illustrated in Figure 5. During retractive movement of the mandrel 84,the members I and II32 are moved with the mandrel '84 and the projections thereon slide into the recesses formed by the projections I50 on the member I42. The muiiler may be stripped off of the mandrels .84 without engaging the front surface I49 of member I42. .Should one end of the .mufiier shell move with'one of the mandrels 84, it will be stripped when the and edge of the shell abuts or engages .suria'ce I 49 during retractive movement of the mandrel.

At the completion of a grooving operation, switching means energize solenoids 165 to elevate the arms I80 to work supporting position. 'When the work supporting mandrels 84 are completely retracted, and the grooved shell is supported upon the arms I80,.switchin g means then operate to de-energize the solenoids, permitting the arms I "to fall or swing downwardly and direct the shell on to the'ramp I15 formed'at the rear dtthe machine for discharging the grooved shells.

It "is apparent that, within the scope of the invention, modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all varia-, tions thereof.

Whatwe claim is:

1. In combination, a frame; a work supporting mandrel mounted upon said support; an annular member surrounding said mandrel and adapted toengage and position the work upon the mandrel; a st ipper ring "surrounding said annular member; said annular member and stripper ring being formed with interengaging projections whereby the annular member is adapted for slidable movement within said stripper ring upon longitudinal movement of said mandrel; said stripper ring being arranged to engage and strip the work from the mandrel during retractive movement of said mandrel.

1 2. 'In combination, a frame; a work piece supporting-mandrel mounted upon said support; an annular member carried by said mandrel and adapted to position the work piece; a stripper ring mounted upon said housing; said annular member and stripper 'ring having interengaging projections whereby said stripper ring is rotatable with said annular member; said mandrel and annular member being arranged for slidable movement relative to said stripper ring whereby the latter engages and strips the work piece from the mandrel.

13. In combinatioma support; a work piece supportingmandrel mounted upon said support; an annular member .carried by said mandrel and adapted to position the work piece; a stripper ring Journaled for rotary movement upon said housing; said annular member and stripper ring having interlocking portions; said mandrel and annular member being arranged for slidable movement relative to said stripper ring whereby the :latter engages and strips the work piece from the mandrel.

4.1m combination, a support; a work piece supporting mandrel mounted upon said support; an annular member carried by said mandrel and adapted to position the work piece; a relatively stationary stripperring mounted upon said hous-. ing and surrounding said'annular member; said annular member and stripper ring having interengagingcportions; said mandrel and annular member :being arranged for slidable movement relative to said stripper ring whereby the latter engages and strips the work piece from the mandrel.

5.111 combination, a support; a work piece supporting mandrel mounted for slidable and rotational movement upon said support; a work piece positioning ring mounted upon said mandrel; a stripper ring mounted upon said support; said rings having interengaging I splines formed thereon; said mandrel and positioning ring arranged to be retracted within the stripper ring whereby the workpiece is caused to engage thestripper ring to remove the work piece from said mandrel.

6. In combination, means vfor impressing grooves in the walls .of muffler shells including a frame; a housing'supported upon the frame; a shell supporting mandrel associated with said housing for rotary :and longitudinal movement with respect thereto; a shell positioning abutment associated with said mandrel; a stripper ring carried by said housing; means including a projection formed upon said abutment and in interengaging relation with said stripper ring whereby the latter is adapted for rotative movement with said shell positioning abutment, and means for retracting said mandrel whereby said stripper ring engages and removes the shell from the mandrel.

7. In combination, means for grooves in the walls of muffler shells including a frame; a housing supported upon the frame; a shell supporting mandrel associated with said housing for rotary and longitudinal movement with respect thereto; a shell positioning ring carried by said mandrel; a stripper ring carried by said housing; means including a plurality of projections formed upon each of said rings and in interengaging relation whereby said stripper ring is adapted for rotative movement with said shell positioning ring, and means for retracting said mandrel whereby said stripper ring engages and removes the shell from the mandrel.

8. In combination, means for impressing a groove in a thin walled member including a frame; a pair of spaced housings supported upon said frame; a mandrel adapted to support the thin walled member movably mounted upon each of said housings; a grooving means adapted to engage and impress a groove in the thin walled member; an annular member mounted upon said mandrel and movable therewith for positioning the thin walled member; .said annular member having a plurality of radially arranged projections formed thereon; a second annular member associated with said housing formed with projections engageable with the projections on said first annular member; said mandrel and first annular member being arranged for longitudinal movement relative to the said second annular member whereby the thin walled member in engagement with said mandrel is stripped therefrom upon longitudinal movement of said mandrel.

9. In combination, means for impressing a groove in a thin walled member including a frame; a housing supported upon said frame; a mandrel adapted to support the thin walled member movably mounted upon said housing; grooving means adapted to engage and impress a groove in the thin walled member; an annular member mounted upon said mandrel and movable therewith for positioning the thin walled member; said annular member having a plurality of radially arranged projections formed thereon; a second annular member associated with said housing formed with projections engageable with the projections on said first annular member; said mandrel and first annular member being arranged for longitudinal movement relative to the said second annular member whereby the thin walled member engages said second annular member and is disengaged from said mandrel.

10. In combination, means for impressing grooves in the walls of muilier shells including a frame; a pair of housings supported upon said frame; a mandrel mounted in each of said nous-- lugs and arranged for longitudinal and rotational movement relative thereto; said mandrels adapted to support a muffler shell; a grooving means mounted upon said frame and movable into engagement with a muffler shell for forming annular grooves therein; a pair of rings surrounding each of said mandrels; resilient means impressing 1 interposed between said rings; a stripper member surrounding said rings; said rings and stripper member being formed with interengaging proa mandrel mounted in Said housing and ar-,

ranged for longitudinal and rotational movement relative thereto; said mandrel adapted to support a muffler shell, a grooving means mounted upon said frame and movable into engagement with a muiiler shell for forming annular grooves therein; a pair of rings mounted upon and surrounding saidniandrel and adapted to position a shell upon the mandrel: resilient means interposed between said rings; a stripper member sur 7 rounding said rings; said rings and stripper mem--' ber being formed with radially arranged projections adapted for interengagement whereby said stripper member is rotatable with said rings and said rings are relatively slidable with respect to said stripper member.

12. In combination, means for impressing grooves in the walls of muiiler shells including a frame; a pair of housings supported upon said frame; a mandrel mounted in each of said housings and arranged for longitudinal and rotational movement relative thereto; said mandrels adapted to support a muiiier shell, a grooving means mounted upon said frame and movable into a muflier shell for forming annular grooves therein; a pair of rings surrounding each of said mandrels and mounted thereon for positioning a shell on said mandrels; resilient means interposed be- 1 tween said rings; a stripper member surrounding said rings; said rings and stripper member being formed with radially arranged projections adapted for interengagement whereby said stripper member is rotatable with said rings and said rings arranged for relative slidable movement axially of said stripper member.

3. In combination, means for impressing grooves in a thin walled hollow member including a frame; a housing supported upon said frame; means for supporting the hollow member during grooving operations including a mandrel mounted on said housing and relatively movable with respect thereto; a, ring surrounding the mandrel and adapted for engagement with the hollow member for positioning the latter upon the mandrel; a stripper mounted upon said housing; interengaging means on said ring and stripper whereby said ring is adapted for relative slidable movement and for simultaneous rotary movement with respect to said stripper; said stripper being arranged whereby engagement of stripper with the hollow member upon retractive movement of the mandrel will disengage the member from the mandrel.

14. In combination, means for impressing grooves in a thin walled hollow member including a frame; a housing supported upon said frame; means for supporting the hollow member during grooving operations including a mandrel mounted on said housing and relatively movable with respect thereto; a ring surrounding the mandrel and adapted for engagement with the hollow member for positioning the latter upon the mandrel; said ring having a convex inner surface adjacent said mandrel; a second ring arranged adjacent said first mentioned ring; resilient.

means disposed between said rings; a, stripper mounted upon sai'd'housi'ng; interengaging means on said rings and stripper whereby said rings are adapted for relative slldable movement and. for simultaneous rotary movement with respect to said stripper; said stripper being arranged tioned ring; resilient means disposed between said rings; a stripper mounted uponea'chof saidihouse 'i i'ngs; interengaging' means on said rings and"; stripper whereby said rings are adapted for relative slidable movement and for simultaneous rotary movement with respect to said? stripper, said stripper being arranged whereby engagement of either with the hollow member upon retractive movement of the mandrels' will strip the member from the mandrel adjacent thereto.

ARTHUR J.

RAYMOND J. DWYER.

REFERENCES CITED- The following references are of record in the tile of this patent;

UNITED STATES PATENTS Number Name Date.

1,952,857 Grotnes Mar. 27; 193! 2,089,475 Grotnes Aug. 10, 1937 2,122,525 Huntsman July 5,,1938 

